Cylinder and piston construction



July 15, 1952 c. c. MITCHELL 2,603,190

- CYLINDER AND PISTON CONSTRUCTION 2 SHEETS-Sl-EET 1 Filed July 7, 1949 y 9 1952 c. c. MITCHELL CYLINDER AND PISTON CONSTRUCTION A '2 SHEETSSHEET 2 Filed July 7, 1949 f INVENTOR. LIN MITCHELL BY Y zaw 2am; flaw,

ATTORNEYS Patented July 15, 1952 CYLINI SERAND. BISTON -GNS1TRUCTION.

Ooliir 'Gampbelb Mitchell, Edinburgh, Scotland;

' assignor i to- Brown Brothers;& --Co. Limited;

Edinburgh, Scotland, a, company of? Great") Britainz.'andzz Northern Ireland:

Application Jam-7; 1949, Serial'No; 103;5203 me'mamrmm June 12; 1948;

' 82Glaims:

This inventionrrelates" o'-acylinderandpiston construction" of that type in: which the=-cyli-nder" wall'is slotted' and the'piston-is provided withanactuating membenprojecting: through the-slot and, adapted in'its travel axially-of the cylinder cylinder: v

Heretofoie it has been" necessary;- to surround the' cylinder byj a heavy framing-of horseshoe shape in cross* section in order 3 to-- restorethe strength and rigidity-forfeited'by the slottingof the "cylinder" Wall An" object 'of the invention -is--toEdispense-with such framing andthereby toaefiecta substantial saving "in weight. I

A cylinder and -piston construction according to =the-i1ivention comprises a cylindenzthe wall of which isfdrmedwith "a" longitudinal *slot; the

marginal portions of the-wall boundingthe slot each presenting an" upstanding longitudinal flangeyoneflange side remote =from-thet slot: being stepped,"- a" flexible" bridging strip normally, resting'ontheshoulder of the-step, a-clampmem-'- ber substantially -of O-shape-in-cross-section emabracingj the two-flanges onetip; of the clamp;

member-abuttingagainst the unstepped flange,- and the, inner edge. .ofrthe. othentip of the clamp memberbeing steppedtoengageone edge of the flexible bridging strip and being spaced from the adjacent flange; the b'ridgingstrip substantially filling: the gap between; said: secondementioned tip of the clamp member and said'stepped" flange, a main piston slidable in said cylinder, means connected to said piston to--flexthe strip and raise an: adjacent portionio-fz it away from the:

shoulder: of the stepped:v flange; and from. the secondmentioned tip, .anactuating-bar movable with said piston and projecting through the gap presented by the raised portion of the strip to the exterior of the cylinder, said bar being connectible to mechanism to be operated by movement of said piston, means connected to said piston to press said strip back into place after passage of the means to flex said strip, and a sealing piston slidable within the clamp member and connected to said main piston, said sealing piston conforming in shape to the interior profile of the clamp member.

The means to flex the bridging strip and to press it back into the checks may be shoes connected to the main piston and bearing against opposite faces of the strip.

The flange against which one tip of the clamp member abuts may be formed with a longitudinal groove of semi-circular cross section, the end of the: abutting; tip: oi; thee clamp; member; being roundedtormate c-with saidtgroovea: Alternativelyysaid :lastementionedffiange may: presentra 1011- gitudinal; ridge: engageable; with; a longitudinal groove: of: semiscircularzcross: section formed in the-*clamprmember:

A2; practical; embodimentl. of: the invention is illustrated: in; the: accompanying": drawings in which Fig; 1 is a side; view -of:a portion*of;'a' .cylim der, Fig. 2 is a sectionzthrough;Ze-Zlihryllig: 1; 3 is; a section througiiz3;-3; int-Fig; 1; Fig. 4 is perspectiyeiview' of; a; portion: of; a1 cylinder dissected to showthaseaiingzstripitandrl figa 5.;is

perspective: view of: at; larger'rportiont of: the cylinder with the clamp omittedito: showrthea shoes;

In the drawings: I denotes:the cyflinderislotted longitudinally-at"2;; 3; ands 4 denote-1v upstanding flanges-houndingwthe:slotgZ ,coneaedgezofrthe: flange 4r b'eingastepped at? 5:. 6::denotesia'.:.clamp;: meme hen-substantially: of ac-shaperintcross section, the inner edge of one tip of the clamps-member: 6'

being stepped-at];- andtheother tip being-arounded at 83300:, engage rooveafiifof semiecircularreross :v section: formed:; in; the: flange: 3; I0:- denotesi a flexiblegbridgingz strip: :engagea-ble L-With: the. steps 1 mandi'h.v II denotes:a2maiuzpistonzslidable. in the cylinderrlyz I 2-;-denotes:aashoe connected tothezpiston; I I 3 and adaptedstocraise? the: adjacent portion: oiirthe iStI'ipl I I): OllfiLOffthGfiStfiDS 51a and 7;

and: I 3: dBIlOtGSQfilSI-ZCOIId'Z hoe; corm'ectedcto the pistorr, I I and adapted: to: pressithestrip I Il into i the checks 5 and I. I4 denotes ianiactuatingi bar fixedito' the: shoe 'I 2,v ,saidzgb'ars being I conneetible to; mechanism; to bee operatedt by movement of the A piston t I I I55 denotes a:sea1ing pistcn..connected to :the pistom IsI: conforming inshape to the interior profile of the clamp member 6 and slidable within the clamp member 6.

In practice, the power stroke of the main piston II is to the right as viewed in Fig. 1. As the piston II moves to the right, the shoe I2 moving with the piston II flexes the adjacent portion of the strip I 0 and raises it from the shoulders of the steps 5 and 1. The actuating bar I 4 moving with the piston operates the mechanism to which it is connected. The shoe I3 moving with the piston I in the wake of the shoe I2 presses the strip I0 against the steps 5 and 1, and the sealing piston I5 also moving with the main piston II prevents pressure fluid in the left hand end of the cylinder from escaping along the clamp member to the right hand end of the cylinder. The higher the pressure in the left hand end of the cylinder I, the more effective is Ff Z; 2,603,190

the sealing action of the strip [0. When the cylinder I is under pressure, the slot 2 tends to widen, the strip I0 being thus jammed between the flange 4 and the adjacent tip of the clamp member 6. Additionally, the pressure of the fluid in the left hand end of the cylinder urges the striplllefurther into engagement with the steps 5 and 1.

What is claimed is:

1. In a cylinder and piston construction in, which the wall of the cylinder has a' longitudinal slot in which an actuating member operated'by the piston moves, a pair of outstanding longitudinal flanges extending lengthwise of said cylinder and bounding the edges of said slot, a clamping member extending longitudinally of the slot and having one portion thereof bearing against a first one of said flanges and a second portion thereof adjacent but spaced from a second one of said pair of flanges to provide a gap between said second portion of the clamping member and said second flange through which a portion of the actuating member may extend, a bridging member adapted to fit into said gap, means operated by the piston to move the portion of the bridging member adjacent the portion of the actuating member which extends through the gap out of the gap, and other means operated by the piston to move the bridging member back into the 'gap after passage of the actuating member.

2. The apparatus defined in claim 1 in which said second flange has a step formed'on the side remote from the slot and the bridging member lies upon the shoulder of said step over at least part of its length. r

3. The apparatus deflned in claim 2 in which the clamping member is substantially C-shaped in cross-section, and said second portion of the clamping member has a step formed thereon, the bridging member lying against the shoulder of the step of the clamping member over at least a part of its length. a

4. The apparatus defined in claim 1 in which both of said means operated by the piston are shoes connected to the piston by means extending through the slot, the shoe of the first-mentioned means operated'by the piston having a fac bearing against one side of the bridging member to force the bridging member out of said gap and the shoe of said other means operated by the piston having a face bearing against the opposite" side of the bridging member to force the bridging memberinto the gap." r

5. The apparatus defined in claim 1 having sealing means for preventing escape of fluid through the slot from one side of the piston to the other side thereof, said sealing means being movable lengthwise of said cylinder by movement of the piston.

6. The apparatus defined in claim 5 in which said sealing means is slidable within the clamping member and conforms in shape to the inner face thereof. n

7. In a cylinder and piston construction in which the wall of the cylinder has a longitudinal slot in which an actuating member operated by the piston moves, a pair of outstanding flanges integral with said cylinder, the opposing faces of said flanges bounding the longitudinal edges of the slot, a clamping member substantially C shaped in cross-section extending longitudinally of the slot and having one of its lateral extremities bearing against a first one of said pair or flanges and having its lateral extremity remote "from the first-mentioned lateral extremity adjacent but spaced from a second one of said pair of flanges to provide a gap between said remote lateral extremity of the clamping member and said second flange through which a portion of said actuating member may extend, said second flange having a step formed on the face remote from the slot and said remote lateral extremity of the clamping member having a step formed thereon, a bridging member adapted to flt into and substantially close said gap, said bridging member lying against the shoulder of the step formed on the second flange and the shoulder of the step formed on said remote extremity of the clamping member, a first shoe connected to the piston and having a face thereof adapted upon movement of the piston to move the portion of the bridging member adjacent said portion of the actuating member out of the gap, and a second shoe connected to the piston and having :a face thereof adapted upon movement of the piston to move the bridging member back into the gap after passage of the actuating member. 7

8. The apparatus defined in claim 7 which has a sealing block connected to thepiston and positioned adjacent said second shoe, said sealing block conforming in shape to the interior outline of the clamping member to prevent passage of fluid from one side of the piston to the other.

COLIN CAMPBELL MITCHELL,

REFERENCES CITED Thefollowing references are of record in the flle of this patent:

FOREIGN PATENTS Number Country Date 470,088 Great Britain Aug. 3, 1937 471,055

Great Britain Aug. 27, 1937 

